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Wiki Sudden Loss Of Range With 2019.16.x Software

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My guess is the constant cooling required. My car's HVAC was running non-stop for about 10 minutes after I exited the vehicle, presumably cooling the battery. I had never noticed this behavior before all of the recent updates that messed with our batteries.

Same here. I think it started sometime during fall. Often it's not worth charging to 90% b/c pump appears to run, not to cool the battery, but actually to reduce the charge to a specific level. It will run until it hits about 82% or so, regardless of outside temperature being hot, cold or in between.
Essentially, now, it is only worth charging to 90% if you will use it immediately, otherwise, the pump will continuously run, so part of your charging will be useless and waste of money. Let me give an example.

During winter, due to batteyrgate, to make a day ski trip, I had to charge ~95%. I would plug it in at night, schedule charge to target 95% a bit before I plan to leave. When I get in car, it would not be at 95%. The car would charge to 95%, and then stop charging and turn on the pump to drain the battery, and consequently it could be at any percentage when you get in the car. It is extremely frustrating.

Between batterygate, chargegate and draingate, I feel like I shouldn't charge any more above 175mi, which means realistic loss is more like 20% (from just previous 90%, not to even mention 100%), and that happened overnight. I still like my car no doubt, but part of its value I specifically paid for was taken away with SW update, and the company is not hearing its customers.
 
I honestly think it's both. Thermal propagation is what they're trying to avoid - it's basically the only way those parked cars could catch fire after sitting still and "cooling down" unused for so many hours. Something in our batteries keeps warming up - and higher energy states seem to be what Tesla is avoiding. The band-aid is capped voltages, limiting maximum energy state with a hard cap on total battery performance. The secondary band-aid is lower temperatures from charging (causing early and rapid taper). Then there's reduced regen, and higher cutoff temperatures when regen is limited - they want to keep the battery from heating up when already cold. A less noticeable band-aid is reducing voltages as quickly as possible, with power waste that just happens to also reduce battery temperatures (and possibly slow down a runaway thermal cascade in the battery).

Reducing charge cools the battery too. Higher states of charge are more stressful and the fires show that batteries that should be cool are heating up on their own, rapidly. This is the biggest danger Tesla isn't talking about, the one they need to disclose and recall for all impacted hardware. Band aids are not OK.
 
Is "the constant cooling required" or "not to cool the battery, but actually to reduce the charge to a specific level" to prevent fire?

A rhetorical question on my part though.
good question. And makes me think, I don't really hear it at 50%. I do hear a fan and something more loud if it's hot outside, and I was driving for a while, and then park.
But this sounds different. It's actually quieter, and just goes on. It'd be nice to know why.

I would be ok with it if there was a X% of battery reserved for just battery management and customers still got what they paid for, eg. 100D would have a 110kW battery, but only 100kW accessible for customer use. And that's at the core of this problem. Seems like post sale they figured out technology is not quite ready, and decided to band-aid it at consumer cost.
 
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Here are some screen shots. I uploaded 2020.20.1 a couple of days ago. Notice how my "usable full pack" keeps changing from update to update

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I haven't been on here for a while but had plenty of time in my car monitoring things.

My battery is definitely degrading. For the first 4-5 years it lost capacity gradually while still remaining well in balance. Over the last year or so it's going downhill faster. The cell balance has gone from 4 mV to 40 mV. Nothing I tried helped improve that. I tried charging to 100% then driving down to 2%, AC charging vs DC charging, letting the car sit for a few days, doing just partial charging. Nothing makes any difference. (Confirms one more time that cell balancing doesn't need any specific procedure or state to work).

As others have noticed as well, thermal management has been adjusted to keep the battery cool, especially at higher SoC. But for some reason Tesla has not address another issue that results in my battery running extremely hot almost all the time. The power train cooling in the Model S/X is not good. It works OK when you drive freeway speed, but in low speed city traffic, the drive unit warms up even when driving carefully. Once a certain temperature in the drive unit coolant loop is reached, the car will use the AC system to cool it down. It directs the coolant through the chiller unit into the drive unit. Looking at the temperatures using ScanMyTesla I can see exactly when it changes the coolant loop. Unfortunately on the outgoing side the coolant goes into the battery! Now the drive unit operates at a much higher temperature level than the battery. What is relatively cool to the drive unit is still very hot for the battery. As a result when the drive unit need cooling and the car does so, it sends the output into the battery and heats it up. If you drive lower speeds and stop a lot at red lights or in traffic, this happens on a regular basis. I guess the lack of airflow causes the drive unit to build up heat. On a day where I drive a lot, I always get my battery way above 40 Celsius because of that unfortunate heat dumping into the battery. By the time I'm getting down to 30% my battery is often 50 Celsius. Just to give you a perspective, at 53 C the car will start to limit power from and to the battery to protect it. Since I drive a lot I found that my battery spends a lot of time at very hot temperatures which isn't good for longevity.

I have been monitoring battery temperatures over years and I found it got worse in the last year or so. Maybe the increased internal resistance also contributes to that.
 
But for some reason Tesla has not address another issue that results in my battery running extremely hot almost all the time.
They "addressed" it by keeping battery cooling on all of the time. That warmer than usual temperature is what causes Teslas to catch fires. We almost certainly have lithium dendrites caused by fast charging. If you look up lithium dendrites, they slowly heat up by constantly maintaining an electrical current when the battery shouldn't, like tiny little short circuits.

This form of uncontrollable heating up is probably the indirect way Tesla is trying to detect batteries about to combust and switching those from "Just Chargegate" nerfed (chargegate being the nerf that they hope stops more dendrites from forming) to Batterygate nerfed (batteries they have identified as an imminent mortal danger in need of severe (but cheaply applied) response. They can't detect dendrites, there is no sensor for that. There are a couple of temperature sensors inside of each battery module though, and if one is heating up when it should be cooling down.... Tesla already told us "A single module" caused the explosive conflagration caught on video, and thermal runaway is how that would happen from a single module without physical damage.... thermal runaway caused by a tiny uncontrollable short circuit slowly heating up one cell, then the next cell, then the ones around them, and so on until the heat was enough to expand larger than the size of the car in a nanosecond.

This logical train of thought is also why I haven't parked indoors or near other cars or buildings since I realized what was going on. Tesla expects batterygate limited cars to burn, can't afford to recall them, and is risking our lives in the hopes they can cover it all up forever. They think they can cool down cells that are trying to burn constantly wit hthese tiny shorts creating nonstop heat, they think they can reduce the amount of energy in the cell enough that it won't be able to jump those tiny arcs any more. They think there aren't any legal objections to covering this all up, that safety is unimportant, that cars won't burn any more and people will be thankful for the secrets.

If you look at every single negative update since those fires focused attention on an inherent flaw within our batteries, it all points at what looks like Tesla believing lithium dendrites are the cause. Reduced charging to slow the formation of more dendrites. Increased cooling for absurdly long amounts of time to keep thermal runaway in check until the battery's SOC falls low enough to hopefully stop shorting, so it can cool down on its own.

If you research lithium dendrites every scientific publication will explain how they are exceptionally dangerous for these reasons. It all fits. Unfortunately, since lithium dendrites are completely undetectable until they are actively trying to start a fire, the only solution to a deployed series of batteries that catch fire from them when used as intended is to replace all of them. Hundreds of thousands of batteries need to be recalled... Tesla realized they can't do that, so they came up with an illegal response: Chargegate/Batterygate. Chargegate tries to mitigate the cause of the fires. Batterygate is trying to mitigate the fires themselves after they are predicted in specific cars. This isn't just a band aid in my mind, the band aid is chargegate. Batterygate is a quarantine - they are hoping to "flatten the curve" of heat propagation low enough that coolant enough can keep temps below the flashpoint.
 
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They "addressed" it by keeping battery cooling on all of the time. That warmer than usual temperature is what causes Teslas to catch fires. We almost certainly have lithium dendrites caused by fast charging. If you look up lithium dendrites, they slowly heat up by constantly maintaining an electrical current when the battery shouldn't, like tiny little short circuits.
You realize this has absolutely nothing to do with what @David99 was talking about (ie, the post you quoted), right?

David was talking about the plumbing of the cooling system, and the fact that the chiller is arguably undersized for the motor's heat output. Nothing about dendrites, batterygate, or chargegate.
 
I realize you should reread the post you're misunderstanding. David's battery is constantly short circuiting from lithium dendrites - probably only in one or 2 modules, or even one or 2 cells. The failing ones need constant cooling, and the cells that are under a nearly permanent load (which is why they need cooling) are degrading rapidly and falling out of balance with the rest of the pack from the unstoppable load and wear caused by those dendrites.

Tesla's problem with cooling is why Teslas catch fire, and why David posted here.
 
I wonder if LSD-NiMH batteries would have been a better choice.
They can't charge as fast, however. But too much fast charging eventually destroys Li-Ion batteries.

The grouping of series vs parallel would have to be completely redone to get a decent total pack voltage since a single NiMH cell is 1.25V fully charged, so 6s*74p ("85")/6s*86p ("100") in a single module would have to become 24s*19p ("85")/24s*22p ("100") which would give each module a fully charged 30.0V vs 25.2V. 16-module packs would be 480V, 14-module packs 420V.

Some hybrids use NiMH packs instead of Li-Ion, the Toyota Avalon hybrid comes to mind.
But there's no need to fast-charge a hybrid pack.
 
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Some hybrids use NiMH packs instead of Li-Ion, the Toyota Avalon hybrid comes to mind.
But there's no need to fast-charge a hybrid pack.

Not quite.

Regenerative braking force of 15 kW with a 3 kWh pack is equivalent or even more intense compared to supercharging a 75 kWh pack at 210 kW ... the C rate of the battery charge is the key, meaning, hybrids with small packs do have similarity to DC fast charging, but do so much more often because there's a lot of stop lights in the world, vs fast chargers!